Formwork for manufacturing a concrete structure, formwork system for forming such a formwork and method for manufacturing a concrete structure

ABSTRACT

A formwork for manufacturing a concrete structure which is composed of one or several folding portions, provided with one or several hollow portions which in an unfolded and stretched condition have the shape of the contours of portions of the concrete structure to be formed, whereby the formwork can be placed on a bottom in an initial condition and whereby, by pouring or pumping concrete slurry in the hollow portions of the formwork, the formwork can be taken from the initial condition to the stretched condition so as to form the respective portions of the concrete structure.

The present invention first of all relates to a formwork formanufacturing a concrete structure.

The invention also relates to a method for manufacturing such a concretestructure.

Without restricting the invention thereto, the invention may be of greatpractical use for manufacturing concrete foundations, rainwater bufferbasins, rain water infiltration basins, basements, crawl spaces and soon.

However, the invention may just as well be applied in other domains thanconstruction and architecture, for example for manufacturing any supportstructure whatsoever, such as for example vertical columns, walls,partitions, floor slabs, arches and vaults.

Naturally, many types of formworks and methods for manufacturingconcrete structures are already known, but they represent a number ofdisadvantages.

In a conventional formwork, a mould is made of plates which need to beanchored in a surrounding structure or which need to be propped up bymeans of beams, struts and the like.

In what are called modular formworks, use is made of standard formworkelements that are connected to one another and are supported on thebuilding site.

Many other techniques are known as well, but they all require a certaindegree of anchorage or support of the formwork with respect to anexisting surface or already built-up structure.

A first major disadvantage of these known formworks and methods formanufacturing a concrete structure consists in that putting the formworkin place and supporting it requires a lot of operations, and thus a lotof working hours, as well as an adequate knowledge of the workmen.

All of the above is also disadvantageous to the cost price of the works.

Another disadvantage of the aforesaid known formworks and methods isthat they require a lot of material, a large part of which is often notre-usable.

This has for a result that, after the concrete has cured, a large amountof waste remains, and large quantities of material such as wood areconsumed.

This is not only detrimental to the environment but also, again, to thecost of these techniques.

An additional disadvantage of these known formworks and methods is thatthe material which is used for the formwork and its support is veryheavy, whereby great physical effort is often required from the workersand/or use must be made of large machines such as lorries, cranes,forklifts and all sorts of other lifting equipment for the transport andpositioning of the components required for the formwork.

Yet another disadvantage of the known formworks and methods formanufacturing a concrete structure consists in that it is difficult toabsorb any unevennesses in the substrate or alignment errors in theexisting structure, resulting in that a highly accurate preparation andprecision are required during the execution of the works, for examplethe digging of a building pit, and/or in that the positioning andsupport of the formwork is associated with all sorts of time-consumingcustom work.

Also, the present invention aims to remedy one or several of thepreceding disadvantages and possibly other disadvantages as well.

The invention aims in particular to provide a formwork and method withwhich a concrete structure can be manufactured in an extremely fast andefficient manner, whereby the number of steps during its production arerestricted to a minimum.

Another aim of the invention is to achieve a formwork for manufacturinga concrete structure requiring little skill for its use.

Yet another aim of the invention is to obtain a formwork which stands onits own and which is self-supporting and with which a concrete structuremay be formed, such as for example typically a water infiltration basinor a basement, wherein no or hardly any additional elements must beprovided for the anchoring and support of the formwork in relation tothe substrate or existing structure during the works.

Yet another object of the invention is to obtain a formwork which isvery light and which can be easily placed on a substrate.

Additionally, it is an object of the invention to provide a formworkwith which unevennesses, oblique positions and/or inaccuracies in theadjacent structures are automatically absorbed.

To this end, the present invention concerns a formwork for manufacturinga structure which is composed of one or several flexible foldingportions in the shape of a fabric, membrane or fleece, whereby theformwork is foldable and is provided with one or several hollow and/orbag-like portions in which a filler may be applied and which, in anunfolded and stretched condition have the shape of the contours ofportions of the structure to be formed, and whereby the formwork can beplaced on a bottom in an initial condition, which is a folded conditionor an either or not entirely unfolded condition of the formwork, andwhereby by pouring or pumping filler in the hollow and/or bag-likeportions of the formwork, the formwork is gradually taken from theinitial condition to the stretched condition so as to form therespective portions of the structure.

A first major advantage of a formwork according to the invention is thatit is mainly composed of flexible, foldable material, excluding anyreinforcement such as bars or other materials which may be pre-assembledas well in the foldable formwork.

Thus, such a formwork according to the invention is relatively light inweight compared to the weight of the known formworks, and such aformwork according to the invention can be easily transported as a wholeto a building site, whereby it can be installed on the building sitewithout too much difficulty and, depending on the application, maypossibly be unfolded.

Another advantage of such a formwork according to the invention is thatit can be placed as such on a bottom, in an initial condition, wherebyno or hardly any additional support or anchoring in the bottom or othersurrounding structures is required, possibly with the exception ofsmaller devices such as pins, pegs, hooks or the like for holding theformwork in a specific position on the bottom and/or for keeping theflexible formwork in an entirely unfolded or partially unfoldedcondition.

Thus, a formwork according to the invention is an essentiallyself-contained and self-supporting whole.

This saves a lot of time during the works, since no complex supportingstructures must be erected, nor any heavy materials must be supplied.

Another advantage of a formwork according to the invention consists inthat is provided with hollow portions which optionally form bag-likeportions and which, in an unfolded and stretched condition, adopt thecontours of the concrete structure to be formed.

By a bag-like portion is meant a hollow portion with at least one openend and a closed end, such that when pouring or pumping concrete slurrythrough the open end in the bag-like portion, the concrete slurry willremain in the bag-like portion.

In other cases, the hollow portions may have an entirely closed wallwhich needs to be pierced to insert concrete slurry, or a hollow portionmay be provided with a wall with one or several openings, whereby thehollow portion does not form a bag-like portion in the sense that whenapplying concrete slurry in the hollow portion, the concrete slurrywould normally flow away, but whereby the concrete slurry can beprevented from flowing away, for example by applying one or severalpressure installations, such as a pump or the like, in the opening oropenings concerned.

In any case, it is a major advantage of the invention that the aforesaidhollow or bag-like portions, in a stretched condition, form the contoursof the structure to be manufactured, such that the required shape can beimmediately obtained.

Since the formwork is composed of flexible and folding portions, suchflexible formworks for structures with very different and rather complexshapes can be designed and manufactured beforehand in a relativelysimple manner, for example in a factory building, whereby foldable andflexible portions may be custom-cut and connected to one another, and soon.

Of course, all modern design and manufacturing tools can be used to thatend, such as custom design software, CAD-CAM systems and the like.

The aim of a formwork according to the invention is to be placed on abottom in an initial condition.

This initial condition may be a folded, partially unfolded or entirelyunfolded condition, whereby by pouring and/or pumping filler in thecavities of the bag-like portions of the formwork, the formwork can befurther unfolded as of the initial condition if need be, and put in astretched condition which assumes the shape of the concrete structure tobe manufactured, as it were like a bouncing castle which is inflatedwith air.

Naturally, with such a formwork according to the invention it ispossible to erect structures in a very efficient manner and in no time,which would require an enormous amount of work and material with theknown means.

Another advantage of a formwork according to the invention consists inthat, thanks to its flexible character, unevennesses in a surface can beeasily absorbed, and in that a special design of the formwork makes itpossible for certain portions of the formwork to be automaticallyvertically aligned, irrespective of any inclination of the bottom, atleast within certain limits.

In a possible application, the formwork according to the invention isused for manufacturing a concrete structure, but structures made ofother materials are not excluded either.

Also, the filler may merely consist of concrete slurry, but the fillermay just as well consist of filling material such as sand, Argex grains,air, PU foam, PS granules, water or a combination thereof.

Filling the formwork with filler can be done in one or several steps.

According to a preferred embodiment of a formwork according to theinvention, one or several hollow and/or bag-like portions of theformwork, in an unfolded and stretched condition, have the shape of avertical column of the structure to be manufactured.

Such a hollow and/or bag-like portion of the formwork which is designedas a portion to form a vertical column of a concrete structure may forexample be entirely or partially folded when the formwork is placed on abottom in its initial condition, whereby by pumping concrete slurry insaid hollow or bag-like portion, the formwork will gradually unfold,raise itself and stretch, so that the shape of a vertical column isobtained.

Usually, the concrete slurry will be supplied from below at the heightof the aforesaid bottom in this case.

In other cases, concrete slurry can be inserted in said hollow and/orbag-like portion at a certain height above the bottom in question onwhich the structure is to be erected, for example by pouring theconcrete slurry from a lorry or concrete mixer through an opening and bygradually filling the column as of the bottom.

In this case, such a hollow and/or bag-like portion of the formworkwhich is designed as a portion for forming a vertical column of aconcrete structure is preferably largely or entirely unfolded in theinitial condition, for example by suspending it on a surroundingstructure or with the help of other supporting means, whereby by pumpingor pouring the concrete slurry, the relevant portion is furtherstretched so as to form a vertical column.

It is clear that, in both cases, a formwork according to the inventionoffers many advantages compared to the known formworks, since itspositioning takes little time and since no or only a limited number ofadditional means are required.

In other preferred embodiments of a formwork according to the invention,the formwork additionally or alternatively contains, in a similarmanner, one or several hollow or bag-like portions which, in an unfoldedand stretched condition, have the shape of other elements of theconcrete structure to be manufactured, such as for example:

-   -   hollow or bag-like portions forming adjacent columns so as to        form a vertical wall of the structure;    -   one or several flexible folding portions in the shape of a        fabric, membrane or fleece which, in an unfolded condition of        the formwork, form a flat portion of the formwork for        manufacturing a concrete slab of the structure;    -   tubular hollow portions for forming arc-shaped spans of the        structure to be manufactured;    -   hollow or bag-like portions of the formwork which, in an        unfolded and stretched condition, have the shape of a base of        the concrete structure, for example the shape of a foot, a base        plate or a beam.

Naturally, the list is not limitative, and flexible formworks accordingto the invention with portions which in a stretched condition assumeother shapes for manufacturing an element of a concrete structure may beapplied while still remaining within the scope of the invention.

The invention also relates to a formwork system for forming a formworkaccording to the invention as explained above in order to make itpossible to manufacture a concrete structure according to a pattern withrepeatedly recurring structure portions or with symmetrically providedstructure portions.

In particular, such a formwork system according to the inventioncontains one or several types of flexible and foldable system portionswhereby each system portion of a certain type of system portions alwayshas the same shape corresponding to a specific structure portion to beobtained, and whereby different system portions can be connected to eachother in accordance with the structure pattern to be achieved.

In this way, a kind of standardisation can be obtained, whereby verylarge structures can be realised with merely a few types of systemportions by connecting them according to different patterns.

According to a preferred embodiment of a formwork system according tothe invention, the concrete structure to be manufactured represents aregular pattern of columns which are mutually connected by means ofconnecting portions, and an above-mentioned type of flexible andfoldable system portion corresponds to a vertical section through suchcolumn and one or several associated connecting portions.

Such an embodiment of a formwork system according to the invention isideal for realising water infiltration basins, reservoir basins,rainwater buffer systems or basements and the like, as will be furtherillustrated.

The invention also relates to a method for manufacturing a structurewhich consists in:

-   -   composing a formwork containing one or several flexible folding        portions in the shape of a fabric, membrane or fleece, whereby        the formwork is foldable and is provided with one or several        hollow and/or bag-like portions in which a filler can be        provided and which, in an unfolded and stretched condition, have        the shape of the contours of portions of the structure to be        formed;    -   positioning the formwork on a bottom in an initial condition,        which is a folded condition or an either or not partially        unfolded or entirely unfolded condition;    -   pouring or pumping filler in the cavities of bag-like portions        of the formwork, whereby the formwork is gradually taken from        the initial condition to the stretched condition so as to form        the relevant portions of the structure to be formed; and,    -   making the concrete slurry cure.

The advantages of this method speak for themselves, and further detailswill be further explained by means of the figures.

In order to better explain the characteristics of the invention, thefollowing preferred embodiments of a formwork for manufacturing aconcrete structure, a formwork system for composing such a formwork, aswell as a method for manufacturing a concrete structure according to theinvention are described with reference to the accompanying figures, inwhich:

FIG. 1 is a view in perspective of a first possible embodiment of aformwork according to the invention for manufacturing a rainwater buffersystem, whereby the portions for pouring a top plate have been omitted;

FIG. 2 is a top view according to arrow F2 in FIG. 1;

FIGS. 3 and 4 illustrate in perspective how, in an additional step, aflat portion can be provided on the formwork from FIGS. 1 and 2 forpouring a top plate;

FIG. 5 schematically shows a side view of a rainwater buffer system;

FIG. 6 is a view in perspective of an alternative embodiment of aformwork according to the invention for manufacturing a regular patternof columns that are mutually connected;

FIGS. 7 and 8 represent a variant of the embodiment from FIG. 6, seen inperspective, before the pouring and after the pouring respectively of atop plate on top of the columns;

FIG. 9 shows another embodiment of a formwork according to theinvention, seen in perspective;

FIG. 10 shows a variant of the embodiment of the formwork from FIG. 9,seen in perspective;

FIG. 11 illustrates a possible method according to the invention formanufacturing a vertical column, seen in perspective;

FIGS. 12 to 14 schematically represent another method according to theinvention for manufacturing a rainwater buffer basin;

FIG. 15 illustrates system portions of a formwork system according tothe invention for manufacturing a rainwater buffer basin according to asquare or rectangular pattern, seen in perspective;

FIG. 16 illustrates in perspective how several types of system portionsof a type represented in FIG. 15 can be connected to one another and toother types of system portions so as to form the rainwater buffer basin;

FIGS. 17 and 18 represent, in a similar manner, another possibleembodiment of a formwork system according to the invention;

FIG. 19 schematically and in perspective shows a type of system portionsof yet another formwork system according to the invention;

FIG. 20 shows a section through a concrete structure in perspective soas to illustrate a number of types of system portions of a morerealistic embodiment of a formwork system according to the invention;

FIGS. 21 and 22 illustrate the use of such an embodiment of a formworksystem according to FIG. 20, seen in perspective;

FIG. 23 schematically represents, as in FIG. 19, a type of systemportions of yet another formwork system according to the invention, thistime for realising a rainwater buffer basin according to a hexagonalpattern;

FIGS. 24 to 28 illustrate a possibly more realistic embodiment of such aformwork system according to the invention, seen in perspective,designed for realising a concrete structure according to a hexagonalpattern;

FIG. 29 illustrates a formwork system according to the invention,schematically and in perspective, for realising a rainwater buffer basinaccording to a triangular pattern;

FIG. 30 shows a formwork according to the invention, seen inperspective, with which an arched vault can be obtained;

FIGS. 31 and 32 are a front view and a top view respectively of theformwork from FIG. 30, according to arrows F31 and F32 respectively;

FIG. 33 shows a model in perspective of an application of the formworkfrom FIGS. 30 to 32;

FIG. 34 shows a model in perspective of a formwork according to theinvention with which a rather linear structure can be obtained;

FIG. 35 is a perspective view of an application of the formwork fromFIG. 34;

FIG. 36 shows a top portion of a formwork according to the invention,seen in perspective, for manufacturing a vertical column; and,

FIG. 37 is a top view according to arrow F37 from FIG. 36.

The first embodiment of a formwork 1 according to the invention,represented in FIGS. 1 to 4, is designed for manufacturing a rainwaterbuffer basin 2 or a similar structure such as a crawl space and thelike.

The different elements out of which such a rainwater buffer basin 2 istypically built are schematically represented in FIG. 5.

The rainwater buffer basin 2 hereby forms an underground structure, forexample under a large parking lot or the like, whereby a top plate 3 issupported by a support structure 4 which in this case consists ofconcrete vertical columns 5 which are distributed over the surface ofthe building pit 6 according to a regular pattern, as well as of a pairof opposite side walls 7 which each define an edge of the building pit6.

The columns 5 rest on one or several feet or, as in FIG. 5, on a bottomplate 8 provided on the bottom 9 of the building pit 6.

In the top plate 3 is further usually provided a reinforcement 10, andthe top plate 3 is poured by means of a clamping formwork or hangingformwork 11 on top of the columns 5.

Such rainwater buffer basins 2 are important in that, when it's rainyweather, the large amount of rainwater which ends up for example on aparking lot can be led to the underground rainwater buffer basin 2, forexample by means of drain pipes, to temporarily store the rainwaterthere in the space 12 between the columns 5 so as to further dischargeit to rivers and/or other drains later on, when they have sufficientcapacity to further discharge the rainwater.

According to the known techniques, when building such a rainwater bufferbasin 2, one typically starts with the excavation of a building pit 6whereby, before the actual excavation works begin, the side walls 7 areoften manufactured by means of several ground drillings performedadjacent to one another and which are filled with a concrete slurry andpossibly a reinforcement to form the side walls 7.

The base plate 8 is then poured on the bottom 9 of the building pit 6.

After the base plate 8 has cured, formworks are installed on the spot ofthe vertical columns 5 to be poured and the reinforcement of thesecolumns 5 is further developed, which usually involves the use of many,often heavy materials and supports of all types.

Finally, after the columns 5 have been poured and cured, a formwork isprovided adjacent to the columns 5, and the top plate 3 is poured.

With the known techniques, the latter formwork usually has to besupported again by numerous beams and struts.

It is clear that such a known method requires a huge amount of work andmaterial and is associated with many separate successive steps whereby awaiting period has to be respected each time to allow the pouredconcrete slurry to cure.

With a formwork 1 according to the invention it is possible to apply amethod according to the invention which is much simpler and faster andrequires less separate steps.

Characteristic of such a formwork 1 according to the invention is thatit is composed of one or several flexible folding portions 13 in theshape of a fabric, membrane or fleece, such that a foldable formwork 1is obtained.

These folding portions 13 may for example be woven from fibre materialswith a relatively high tenacity such as fibreglass, jute, Kevlar,polypropylene, nylons and the like, whether or not provided in a matrixof another flexible material, for example by means of melting.

However, it is not excluded according to the invention to manufacturethe folding portions 13 without applying a weaving technique.

The foldable formwork 1 is hereby provided with one or several hollowand/or bag-like portions 14 in which concrete slurry 15 can be provided.

In an unfolded and stretched condition, these hollow and/or bag-likeportions 14 have the shape of the contours of portions of the concretestructure 16 to be obtained, i.e. in this case of portions of therainwater buffer basin 2.

More specifically, the formwork contains several hollow portions 17which, in an unfolded and stretched condition, have the shape of thecontours of a vertical column 5 of the concrete structure 16 to beformed.

These hollow portions 17 are somewhat conical, whereby the section ofthe vertical column 5 to be obtained narrows somewhat towards its top18.

At their tops 18, the hollow portions 17 communicate with a narrowedhollow portion 19 having a cylindrical surface, at least in the unfoldedand stretched condition, and which, after the concrete slurry 15 hasbeen poured and cured, serves as an anchoring element for anchoring eachvertical column 5 to a top plate 3.

For the formation of the side walls 7 of the concrete structure 16, theformwork 1 is further provided with several hollow portions 20 which, inan unfolded and stretched condition, have the shape of a vertical,cylindrical or slightly conical column and whereby the relevant hollowportions 20 are adjacent to one another so as to form such a verticalside wall 7 of the structure 16.

These hollow portions 20 have cylindrical or slightly conical contoursin the unfolded and stretched condition.

The foldable formwork 1 further contains several hollow portions 21which, in an unfolded and stretched condition, together have the shapeof a base 22 of the concrete structure 16.

The hollow portions 17 are erected according to a regular pattern on thebottom 9 of the building pit 6 so as to form vertical columns 5 in asquare pattern, and with a fixed mutual spacing T between two successivecolumns 5.

In the given example, the hollow portions 21 forming the base 22 eachtime connect two successive hollow portions 17 at their bottom side 23.

In the unfolded and stretched condition, the hollow portions 21 have aconcave gradient, such that on each vertical column 5, on its bottomside 23, is formed a widened foot 24.

In the given example, in between four vertical columns 5 standing in asquare, a circular opening 25 is each time formed by the connectinghollow portions 21.

At the position of the vertical columns 5 adjacent to the side walls 7,the hollow portions 21 for the base 22 connect the corresponding hollowportions 17 and 20.

The formwork 1 is further also provided with portions 26 which each timeconnect the tops 18 of successive hollow portions 17 for the verticalcolumns 5 and which serve as connecting pieces 26 for supporting the topplate 3 to be formed.

These portions 26 may be either or not hollow and they also serve asdrawing elements to position the vertical shapes and distribute themwell.

The formwork 1 according to the invention illustrated in FIGS. 1 and 2has a rather complex shape which corresponds to the complex shape of thecontours of a support structure 4 of a rainwater buffer basin 2.

The different hollow portions 14 may hereby be all mutually connected,or separate compartments may be formed.

Depending on the case, the concrete structure 16 may thus be formed byfilling the entire formwork 1 with concrete slurry 15 all at once, or bypouring or pumping concrete slurry 15 in the separate compartments oneby one.

Furthermore, in an initial condition, the formwork 1 can be placed onthe bottom 9, which according to the invention generally does notcorrespond to what is represented in FIGS. 1 and 2.

For, in the initial condition, the formwork 1 may be entirely folded oreither or not partially or entirely unfolded, for example for applying areinforcement.

It is only by pouring or pumping concrete slurry 15 in the hollow and/orbag-like portions 14 of the formwork 1 that the formwork 1 is graduallytaken from the initial condition to a stretched condition, as isrepresented in FIGS. 1 and 2, so as to form the relative portions of theconcrete structure 16 after the concrete slurry 15 has cured, morespecifically in this case the support structure 4 of the rainwaterbuffer basin 2.

In order to erect and as it were inflate the formwork 1 as of aninitially folded or partially folded condition, concrete slurry 15 canbe pumped in the hollow portions 14 at the level of the bottom 9 of thebuilding pit 6, for example in openings provided in the hollow portions21 for the base 22 or at the bottom side 13 of the hollow portions 17for the vertical columns 5.

The conical shape of the hollow portions 17 creates a counter-pressureas they are being filled up, such that a well stretched whole isobtained.

The aim is to provide an additional portion 27 of the formwork 1, afterthe concrete slurry 15 has cured, on top of the obtained supportstructure 4, more specifically on the portions 17 forming the verticalcolumns 5, the portions 20 forming the side walls 7 and the portions 26forming the connecting pieces.

This additional portion 27 of the formwork 1 is formed, just as theother portions of the formwork 1, by one or several flexible foldingportions 13 in the shape of a fabric, membrane or fleece.

In the given embodiment of FIGS. 1 to 4, this flexible foldable portion27 is a separate portion which, in an unfolded condition of the formwork1, forms a flat portion 27 of the formwork 1.

After this additional flat portion 27 has been applied on the supportstructure 4, it will extend between the portions 17 and 19 of theformwork 1 forming the columns 5 of the structure 5, and a hanging orclamping formwork 11 is formed so to say for realising a top plate 3.

This is represented in FIGS. 3 and 4.

Reinforcement and possibly additional tensioning means may possibly beprovided before pouring a concrete slurry 15 on the flat portions 27 soas to form the top plate 3 of the structure 4.

It is clear that with such a foldable formwork 1 according to theinvention a very efficient method according to the invention can beapplied, requiring only two sessions during which concrete slurry 15 isbeing poured to obtain a structure 4 such as a rainwater buffer basin 2.

This results in a huge reduction of the required waiting times.

Also the preparation of the formwork 1 itself in the building pit 6takes far less time than with the conventional formworks 1.

FIG. 6 represents another embodiment of a formwork 1 according to theinvention for realising a grid of vertical columns 5 in a square patternwhereby successive columns 5 are connected at their bottom sides 23.

The formwork 1 is again composed of flexible folding portions 13 whichall form hollow portions 14, more specifically hollow portions 17 and 19for forming the vertical columns 5 with a narrowed protrusion at thetops 18, as well as hollow portions 21 for the connection betweensuccessive columns 5, which are not concave this time but cylindrical.

Neither hollow portions 20 are provided for forming side walls 7, norhollow portions 26 for the supporting connecting pieces at the tops 18of the columns 5.

The hollow portions 17, 19 and 20 may together form one large cavity orseveral compartments thereof.

With this formwork 1 may be erected a support structure 4 for pouring atop plate 3 in a minimum of time, essentially in the same manner asdescribed above with reference to the preceding embodiment.

After the concrete slurry 15 has cured, a box-shaped formwork can beprovided on the columns 5 for pouring the top plate 3, for exampleaccording to the known techniques or by applying a flat, flexibleportion 27 analogous to what is illustrated in FIGS. 3 and 4 and whichis additionally lined with a border preventing the concrete slurry 15from flowing away.

FIG. 7 shows a variant of the formwork 1 in FIG. 6, whereby the formwork1 is this time additionally provided with several flexible foldingportions 27 in the shape of a fabric, membrane or fleece, which are anintegral part of the formwork 1 and which, in an unfolded condition ofthe formwork 1, form a flat portion 27 of the formwork 1 extendingbetween the hollow portions 17 and 19 of the formwork 1 forming thecolumns 5 of the structure 4, more specifically at the tops 18 of thesecolumns 5.

The aim hereby is that, in a first step of a method according to theinvention, concrete slurry 15 is pumped or poured in the hollow portions17, 19 and 21 so as to form a support structure 4 consisting of a gridof mutually connected vertical columns 5, whereby during the filling,erecting and tightening of said hollow portions 17, 19 and 21, the flatportions 27 simultaneously stretch between the columns 5 while thelatter are being formed.

According to the invention, it is not excluded to unfold the entireformwork 1 as a whole or partially and to stretch it more or less withadditional means, for example for providing a reinforcement, beforeproviding concrete slurry 15.

After the support structure 4 has cured, a top plate 3 of the structure16 may be formed by pouring concrete slurry 15 on the flat portions 27,which is illustrated in FIG. 8, albeit with the top plate 3 raisedsomewhat above the flat portions 27 of the formwork 1.

It is clear that such an embodiment of a formwork 1 according to theinvention makes the construction of for example a rainwater buffer basin2 or any other basement even easier, since while the support structureis being formed, a flat formwork for the top plate 3 is automaticallyand simultaneously unfolded.

FIG. 9 represents another embodiment of a formwork 1 according to theinvention for manufacturing a vertical column 5.

This formwork 1 comprises a bag-shaped flexible portion 17 which, in theunfolded and stretched condition, adopts the shape of the column 5 andwhich is connected to a hollow portion 19 so as to form a narrowedprotrusion on the top 18 of the column 5.

What makes this embodiment of a formwork 1 according to the inventionspecial, is that it also comprises three hollow foldable and flexibleportions 28 which are adjacent to one another and which, in the unfoldedand stretched condition, are at right angles to the vertical column 5,and which thus extend horizontally.

The aim is to first fill these horizontally directed, hollow portions 28with a filler such as sand mortar 29 or the like, so that astabilisation wall or sand buffer 30 is obtained and the hollow portions17 and 19 for the column 5 are also simultaneously unfolded and erected.

The sand mortar 29 requires no curing time, so that the concrete workscan start immediately.

Such a formwork 1 is very practical for example for trench-shapedinfiltration basins, which must usually be provided with a sand buffer30 on both sides.

FIG. 10 shows a variant whereby the foldable formwork 1 is this timeprovided with several vertically directed, hollow portions 17 and 19which are successively provided along the horizontally extending hollowportions 28 so as to form a concrete side wall 7 or a series of columns5 leaning against the stabilisation wall or sand buffer 30.

Naturally, the configurations of FIGS. 9 and 10 can be combined withthose of FIGS. 6 to 8, whereby by making use of said sand buffers 30, atop plate 3 and the support structure 4 can be even pouredsimultaneously, since in this case the top plate 3 immediately findssupport on the sand buffers 30 which are already filled with sand mortarwithout the concrete support structure 4 needing to cure first.

FIG. 11 represents a method according to the invention for manufacturinga concrete structure 16, more specifically a vertical column 5, by meansof a formwork 1 according to the invention.

The formwork 1 is in this case composed of one or several flexiblefolding portions 31 in the shape of a fabric, membrane or fleece,whereby the foldable formwork 1 comprises a bag-like portion 32 with aclosed bottom 33 and wherein concrete slurry 15 can be provided via anopen end 34.

In an unfolded and stretched condition of the formwork 1, the bag-likeportion 32 has the shape of the concrete column 5 to be manufactured,more specifically of a vertical column 5 with a pentagonal cross sectionand with a widened foot 24 and head 18, each in the shape of a frustum35.

The formwork 1 is first put in an initial condition (represented in theleft portion of FIG. 11) by placing it on a bottom 9 and unfolding itand possibly suspending or supporting it with additional means.

A reinforcement may be provided in the cavity of the bag-like portion32.

Via the open end 34 is subsequently poured concrete slurry 15 in thebag-like portion 32 (which is represented in the centre of FIG. 11).

The bag-like portion 32 is hereby gradually filled as of the bottom 9and thus also stretched, so that it adopts the required shape.

Once the concrete slurry 15 has cured, the vertical column 5 is ready,whereby the folding portions 31 can be further removed from the concretecolumn 5, for example by cutting them off.

This situation is represented in the right portion of FIG. 11.

Further, it is not excluded according to the invention for portions ofthe formwork 1 to be part of the concrete structure 16 to bemanufactured, such as in the case of a lost formwork.

FIGS. 12 to 14 illustrate another method according to the invention formanufacturing an infiltration basin or rainwater buffer basin 2 or otherapplications by means of a formwork 1 according to the invention.

The formwork 1 has in this case a shape similar to that in FIGS. 7 and8, save for the fact that one or several hollow portions 17 (or allhollow portions 17 as is the case in the figures) are provided with anopen end 34 on their top side, so that concrete slurry 15 can be pouredin the hollow portions 17 and 21 of the formwork 1 via this open end,for example from a lorry or concrete mixer 36.

In a first step I of the method, the formwork 1 is unfolded and placedin an initial condition on the bottom 9 of a building pit 6.

In a subsequent step II, the hollow portions 21 and 17 are filled withconcrete slurry 15 whereby, thanks to the conical shape of the hollowportions 20, as the concrete slurry 15 rises as of the bottom 9, anupward force F is exerted on the walls of the formwork 1.

This force F contributes to the unfolding and/or erecting and raising ofthe foldable formwork 1, as well as its stretching into the desiredshape in accordance with the contours of the rainwater buffer basin 2 tobe formed.

Simultaneously, thanks to the forces exerted by the concrete slurry 15,the flat portions 27 of the formwork 1 will be stretched, upon which thetop plate 3 is to be poured later on.

The third step III of the method consists of a waiting period for thecuring of the concrete 15 to form the support structure 4 of therainwater buffer basin 2 with columns 5 and a base 22.

In the fourth step IV of the method is then poured concrete slurry 15 onthe flat, flexible portions 27 of the formwork 1 so as to form the topplate 3 which rests on the columns 5 and which cures in step V of themethod.

FIGS. 15 and 16 illustrate a first embodiment of a formwork system 37according to the invention.

The formwork system 37 is designed for composing a formwork 1 accordingto the invention, whereby the aim is more specifically to erect aconcrete structure 16 forming a pattern with repeatedly recurringstructure portions or with symmetrically provided structure portions.

To this end, the formwork system 37 comprises a first type of flexibleand foldable system portions 38, which each have the same shapecorresponding to a particular structure portion to be achieved.

In this case, such a system portion 38 consists of a flexible, foldableportion 40 which, in its unfolded and stretched condition, forms thecontours of a vertical section through a central axis AA′ of a verticalcolumn 5, for example in this case a section through an angle B of 90°.

In the unfolded and stretched condition, the foldable portion 40 has aradially flared portion 41 designed to form a portion of a vault 42extending as of the respective vertical column 5 up to nearby verticalcolumns 5.

Further, the foldable portion 40 is provided with a hollow portion 43 toform a section of a foot 24 on a vertical column 5, as well as a hollowportion 44 to form a rib 45 extending as of the foot 24 of the verticalcolumn 5 to be formed up to the top 46 of the vault 42 to be formed.

The first type of system portions 38 is hereby also provided with ahollow portion 47 for achieving a base 22 for a grid of vertical columns5.

This hollow portion 47 has the shape of a tubular piece 48 designed toform a kind of beam or a connecting portion 49 extending between thefeet 24 of two successive columns 5 of the grid to be obtained.

The formwork system 37 comprises a second type of system portions 39similar to the first type of system portions 38, but whereby the systemportions 39 of the second type are not provided with a hollow portion47.

The different system portions 38 and 39 can be connected to one anotherin accordance with the pattern of the structure 16 to be achieved.

More specifically, four system portions 38 and/or 39 together form asingle hollow vertical column 5, whereby depending on whether more orless connections are required than with other columns 5, more systemportions 38 are used to form the respective column 5.

After the assembly of the formwork 1, which can be done in advance or atthe site itself, the formwork 1 can be unfolded.

By filling the hollow portions 43, 44 and 47 of the formwork 1 with afiller such as concrete slurry or other fillers such as sand, air, PU,Argex grains, water, polystyrene or a combination thereof, a firstsupporting structure 4 can be achieved with annular feet 24 and standingribs 45, whereby the feet 24 are mutually connected by beams 49.

The remaining flexible portions 40 of the formwork 1 are hereby put in astretched condition which is appropriate for filling the cavities 50 inthe vertical columns 5 and for forming the vaults 42 which are supportedby the radially flared portions 41 of the system portions 38 and 39.

In this manner is obtained a very efficient formwork system 37 withwhich numerous configurations can be achieved in a very fast way.

Naturally, many variants of the foregoing are possible, with systemportions provided with several tubular pieces 48 or which enclose avertical section over a larger or smaller angle B of a column 5.

FIGS. 17 and 18 show an alternative embodiment of a formwork system 37according to the invention.

Use is hereby made of a single type of system portions 51 which iscomposed of foldable, flexible portions 52.

In an unfolded and stretched condition, such a system portion 51 assumesthe shape of a hollow column 5, halved according to a verticalintersecting plane CC′ which is somewhat pointed, with a wider foot 24and a narrower top 18.

To this end, the system portion 51 comprises a first hollow portion 53designed to be vertically erected, which is done by filling the hollowformwork 1 with a filler such as for example concrete slurry 15.

At the top 18 of the column 5 to be formed is also provided a narrowedhollow portion 19 to anchor the top of the column 5 in a top plate 3, aswas for example also the case in the embodiment of FIG. 4.

Crosswise to the foot 24 of this half-column 5 and crosswise to theintersecting plane CC′ is further provided a hollow portion 54 designedto be connected to a hollow portion 54 of an adjacent column 5 to beformed.

Thus is obtained a base 22 in the shape of a connecting portion 55 whichconnects the feet 24 of two adjacent columns 5 to be formed.

A column 5 is composed of two system portions 51 which are connected toone another at their intersecting plane CC′.

Several such columns 5 may be connected to one another via the hollowportions 54 which form connecting portions 55.

After pouring a concrete slurry 15 in the respective hollow portions 53and 54, a row 56 of successive columns 5 is thus obtained which areconnected at the feet 24.

In FIG. 18, two such rows of columns 5 are placed parallel to eachanother, after which a flat, flexible and foldable portion 27 isprovided over the tops 18 of the columns 5 for pouring a concrete topplate 3.

In a variant, according to the invention, such a flat portion 27 for atop plate 3 may also be part of the system portion 51, and more or lessrows 56 of columns 5 may be realized, as well as a variety of otherconfigurations.

Instead of composing formworks 1 from several system portions 51,according to the invention, a uniform formwork 1 may of course also bemanufactured at once, out of one piece, without having to connectseveral system portions 51 to that end.

FIG. 19 depicts yet another possible embodiment of a type of systemportions 57 of a formwork system 37 according to the invention.

In this case, such a system portion 57 is composed of foldable andflexible portions 58 which also form a number of hollow portions 19, 59,as well as a bag-like portion 60.

In the unfolded and stretched condition of such a system portion 57, thehollow portion 59 forms a vertical column 5 which is slightly conicalwith a pointed top 18, whereby a narrowed hollow portion 19 is providedto form a protrusion for anchoring the column 5 to be formed on the top18.

In the unfolded and stretched condition, the bag-like portion 60 forms afoot 24 with a square perimeter and with a pyramidal gradient towardsthe column 5.

The system portion 57 is further provided with a flat portion 27provided at the top 18 of the column 5 and which forms an integral partof the system portion 57.

In the unfolded condition, the flat portion 27 of the system portion 57has a square perimeter 61 whose dimensions correspond to the perimeter62 of the foot 24.

Thus, system portions 57 can be coupled to each other as desired on thefour sides of the feet 24 and the corresponding four sides of the flatportion 27 to form a larger whole.

This is illustrated in FIGS. 20 to 22 for an embodiment of a formworksystem 37 which is similar to that of FIG. 19, but which has beendeveloped more realistically.

FIG. 20 is a vertical section through a structure 16 formed with aformwork 1 which is composed on the basis of the aforesaid formworksystem 37 according to the invention, whereby a first type of systemportions 57 corresponds to those of FIG. 19.

The formwork system 37 in the embodiment of FIGS. 20 to 22 alsocomprises other types of system portions 63 and 64 which largely have asimilar shape as the type of system portions 57, but which can be usedto form the edges 65 and the angles 66 respectively of the structure 16.

To this end, the flat portion 27 of the system portions 61 and 62 ispartially vertically connected to the narrowed hollow portion 19 so asto form standing edges 67, so that, after a formwork 1 has beenassembled by coupling the different system portions 57, 63 and 64, as isrepresented for example in FIG. 21, a bag-shaped or rather tub-shapedwhole is obtained on top of the columns 5 which can serve as a formworkfor forming a top plate 3.

The use of the formworks 1 assembled with the here discussed formworksystems 37 is entirely analogous to what was discussed with reference toFIGS. 1 to 10, apart from the fact that complex formworks 1 may beformed, either or not on the building site, on the basis of merely a fewtypes of system portions 57, 63 and 64.

FIG. 21 further illustrates how a reinforcement 68 may be providedbefore concrete slurry 15 is poured on the flat portions 27, whereasFIG. 22 shows the condition after the top plate 3 has been poured,whereby portions of the narrowed hollow portions 19 protrude from thetop plate 3 to possibly serve as anchoring points for any furtherstructure elements that are built on top of the top plate 3.

FIGS. 23 to 28 represent in a similar manner yet another formwork system37 according to the invention which this time comprises system portions69 of a type with a hollow portion 70 for forming vertical columns 5,hollow portions 71 which extend radially as of the foot 24 of a column 5in the radial directions of a hexagon 72 so as to form connectingportions 73 for connecting several system portions 69 at their feet 24.

At the top 18 of a column 5, in the case of FIGS. 24 to 28, are providedsimilar radially extending, hollow portions 74 for forming connectingportions 75 to connect several system portions 69 at their tops 18.

In the case of FIG. 17, the top is provided with a hexagonal flatportion 27 which corresponds to the dimensions of the foot 24.

Thus, different configurations of formworks 1 may be formed according toa hexagonal pattern, as is illustrated for example in FIGS. 26 and 27.

Rather than pouring a top plate 3 afterwards on the support structure 4formed with the system portions 69, use is made of preformed, hexagonalconcrete tiles or plates 76 in the example of FIG. 28 which fit over theprotrusions formed by the narrowed, hollow portions 19 and which rest onthe connecting portions 75 to form a floor or the like.

FIG. 29 represents yet another embodiment of a formwork system 37according to the invention which is entirely analogous to theabove-described cases, but which is based on system portions 77 withwhich triangular configurations can be assembled.

FIGS. 30 to 33 represent yet another embodiment of a formwork 1according to the invention comprising several hollow flexible andfolding portions 78 which in an unfolded and stretched condition havethe shape of an arched span 79 of the structure 16 to be formed.

The hollow portions 78 are cylindrical portions 78 with two open ends 80and 81.

Several hollow, cylindrical portions 78 are disposed adjacent to oneanother and are mutually connected by means of a pair of longitudinalbag-like portions 82 and which are connected to the open ends 80 and 81respectively.

The bag-like portions 82 and 83 form the base 22 of the concretestructure 16 to be achieved.

By pumping concrete slurry 15 in the bag-like portions 82 and 83, theentire formwork 1 is inflated as it were and, as soon as this concreteslurry has cured, a semi-cylindrical vault 84 is thus obtained.

Such a vault 84 may for example be provided in a water gully 85, as isillustrated in FIG. 33, and it may serve to support an overlyingstructure or road or the like.

FIG. 34 represents a formwork 1 according to the invention whichconsists of an elongated structure 86 which extends in a direction DD′and which is formed of one or several rugged, bag-like portions 87.

As is represented in FIG. 35, such a formwork 1 may be used to form asupport structure 24 by filling the bag-like portions with concreteslurry 15.

The support structure 24 may be placed in a water gully 85 to support aroad or the like, while the water 88 can flow between the rugged shapesof the concrete bag-like portions 87.

FIGS. 36 and 37 are views on the open end 89 of a narrowed hollowportion 19 at the top 18 of a vertical column 5 to be formed.

In the narrowed open end 89 are provided flaps 90 which automaticallyclose the open end 89 whenever concrete slurry 15 exerts pressure on theflaps 90 inside the hollow portion 19.

In this manner, a top plate 3 can be immediately poured on a supportstructure 24 without the concrete slurry 15 being already fully cured inthe portion of the formwork 1 of the support structure 24, sinceconcrete slurry 15 is prevented from flowing from this portion of theformwork 1 under the additional pressure of the top plate 3.

Finally, FIGS. 38 to 40 further illustrate that, with a formwork 1according to the invention which is composed of flexible and foldingportions 13, it is easy to take measures to absorb unevennesses in abottom 9 or to automatically vertically align certain portions of theformwork 1.

The invention is by no means restricted to the embodiments of a formwork1 and a formwork system 37 according to the invention, described by wayof example only and illustrated by means of the figures; on thecontrary, formworks 1 and formwork systems 37 may be achieved in manyother ways while still remaining within the scope of the invention.

Nor is the invention restricted to the described examples of methodsaccording to the invention for manufacturing a concrete structure 16; onthe contrary, other methods may be applied while still remaining withinthe scope of the invention.

1. A Formwork for manufacturing a structure, wherein it comprises one orseveral flexible folding portions in the shape of a fabric, membrane orfleece, whereby the formwork is foldable and is provided with one orseveral hollow and/or bag-like portions in which a filler can beprovided and which, in an unfolded and stretched condition, have theshape of the contours of portions of the structure to be formed, andwhereby the formwork can be placed on a bottom in an initial condition,which is a folded condition or an either or not partially or entirelyunfolded condition, and whereby by pouring or pumping filler in thehollow and/or bag-like portions of the formwork, the formwork isgradually taken from the initial condition to the stretched condition soas to form the respective portions of the concrete structure.
 2. Theformwork according to claim 1, wherein one or several hollow and/orbag-like portions of the formwork in the unfolded and stretchedcondition have the shape of a vertical column of the structure to beformed.
 3. The formwork according to claim 2, wherein several hollowand/or bag-like portions of the formwork in the unfolded and stretchedcondition have the shape of a vertical column of the concrete structureto be formed, whereby the respective hollow and/or bag-like portions areadjacent to one another so as to form a vertical wall of the structure.4. The formwork according to claim 2, wherein the formwork comprises oneor several flexible folding portions in the shape of a fabric, membraneor fleece which, in an unfolded condition of the formwork form a flatportion of the formwork which extends between the portions of theformwork forming the columns of the structure and whereby, by pouring afiller on the flat portions, a top plate of the structure can be formed.5. The formwork according to claim 1, wherein one or several hollowand/or bag-like portions of the formwork in an unfolded and stretchedcondition, have the shape of an arched span of the structure to beformed.
 6. The formwork according to claim 1, wherein one or severalhollow and/or bag-like portions of the formwork, in an unfolded andstretched condition, have the shape of a base of the structure to beformed.
 7. The formwork according to claim 6, wherein one or severalhollow and/or bag-like portions of the formwork, in an unfolded andstretched condition, have the shape of a foot, a base plate or a beam.8. The formwork system for forming a formwork according to claim 1, formanufacturing a structure having a pattern with repeatedly recurringstructure portions or with symmetrically placed structure portions,wherein the formwork system comprises one or several types of flexibleand foldable system portions whereby every system portion of a certaintype of system portions always has the same shape corresponding to aspecific structure portion to be achieved, and whereby different systemportions corresponding to the pattern of the structure to be achievedcan be coupled to one another.
 9. The formwork system according to claim8, wherein the structure to be formed contains a regular pattern ofcolumns which are mutually connected by means of connecting portions andwhereby an above-mentioned type of flexible and foldable system portioncorresponds to a vertical section through said column and one or severalaccompanying connecting portions.
 10. A method for manufacturing astructure, wherein it consists in: assembling a formwork comprising oneor several flexible folding portions in the shape of a fabric, membraneor fleece, whereby the foldable formwork is provided with one or severalhollow and/or bag-like portions in which filler can be provided andwhich, in an unfolded and stretched condition, have the shape of thecontours of portions of the structure to be formed; placing the formworkon a bottom in an initial condition, which is a folded condition or aneither or not partially or entirely unfolded condition; pouring orpumping filler in the cavities of bag-like portions of the formworkwhereby the formwork is gradually taken from the initial condition inthe stretched condition so as to form the respective portions of thestructure; and, letting the filler cure.
 11. The method according toclaim 10, wherein the formwork unfolds and is erected as of the bottomwhile filler is being poured or pumped in the hollow or bag-likeportions of the formwork.
 12. The method according to claim 10, whereinthe formwork is provided with one or several hollow and/or bag-likeportions whereby by pouring or pumping the filler in these hollow and/orbag-like portions columns of the concrete structure are formed.
 13. Themethod according to claim 12, wherein the formwork between the hollowand/or bag-like portions forming columns, is provided with flat portionsformed by flexible portions consisting of a fabric, membrane or fleeceand whereby, as soon as the filler has cured in the hollow and/orbag-like portions forming columns, in an additional step of the method,filler is provided on the flat portions so as to form a top plate whichis supported by the columns.
 14. The method according to claim 10,wherein the foldable formwork is provided with one or several hollowand/or bag-like portions, whereby by pouring or pumping the filler inthese hollow and/or bag-like portions, corresponding arched spans of thestructure are formed.
 15. The method according to claim 10, wherein thestructure to be formed shows a pattern with repeatedly recurringstructure portions or with symmetrically placed structure portions andwhereby the formwork is at least partially assembled, on the buildingsite where the structure is to be formed by means of system portions ofa formwork system having a pattern with repeatedly recurring structureportions or with symmetrically placed structure portions, wherein theformwork system comprises one or several types of flexible and foldablesystem portions whereby every system portion of a certain type of systemportions always has the same shape corresponding to a specific structureportion to be achieved, and whereby different system portionscorresponding to the pattern of the structure to be achieved can becoupled to one another, and whereby different system portions arecoupled to one another in accordance with the pattern to be formed ofthe structure.
 16. The method according to claim 10, wherein, whilepouring or pumping, a filler is applied or several fillers are applied,whereby such a filler is one of the following or a combination thereof:a concrete slurry; sand; Argex grains; air; PU foam; PS granules; andwater.
 17. The method according to claim 10, wherein the formwork isfilled in a single step.
 18. The method according to claim 10, whereinthe formwork is filled in several steps.
 19. The method according toclaim 10, wherein the structure to be formed shows a pattern withrepeatedly recurring structure portions or with symmetrically placedstructure portions and whereby the formwork is at least partiallyassembled, on the building site where the structure is to be formed bymeans of system portions of a formwork system wherein the structure tobe formed contains a regular pattern of columns which are mutuallyconnected by means of connecting portions and whereby an above-mentionedtype of flexible and foldable system portion corresponds to a verticalsection through said column and one or several accompanying connectingportions, and whereby different system portions corresponding to thepattern of the structure to be achieved can be coupled to one another,and whereby different system portions are coupled to one another inaccordance with the pattern to be formed of the structure.